The present invention relates to a device for driving, stopping and line-spacing cards or separate forms in an accounting machine, comprising a control unit, a motor controlled by the control unit, a plurality of rollers actuated by the motor for moving the cards or the separate forms for a predetermined number of printing lines, a first coupling device adapted to be activated selectively by the control unit to connect the motor to the rollers, counting means for counting the printing lines, a second coupling device adapted to be activated selectively by the control unit to connect the counting means to the said rollers, and a clutch commanded by the control unit having a driving element connected to the first coupling device and a driven element connected to the counting means. Such an arrangement is hereinafter referred to as an arrangement of the type defined.
Various arrangements for driving cards, or separate forms are known. In these arrangements the positioning of the cards in the printing zone is generally effected manually by raising the paper-gripping rollers by means of a suitable lever and carrying out the alignment of the cards with the printing line by eye, with the aid of a reference index fixed to the machine. In such arrangements the line-spacing is effected automatically by the machine by rotating the platen by one line-spacing step. The positioning of the cards is therefore very slow with respect to the machine cycle times and the line-spacing cannot be carried out on the card independently of other documents passed around the platen.
In other arrangements the drive of the card is effected by means of independently motor-driven rollers employing mechanical clutches controlled by electromagnets for effecting the line-spacing and stopping of the cards. These arrangements are bulky and of considerable structural complexity and have very high actuation times because of the unavoidable delays and inertias of the various moving mechanical parts, these times being no longer compatible with the high working speeds of modern office machines.